沉积体系分析与河道砂岩型铀矿成矿条件讨论——以鄂尔多斯中新生代盆地东胜地区为例  

Analysis on depositional system and discussion on ore-formation conditions of channel sandstone type uranium deposit--taking Dongsheng area,Ordos Meso-Cenozoic basin as an example

作　　者：吴仁贵[1] 陈安平 余达淦[1] 祝民强[1] 周万蓬[1] 

机构地区：[1]东华理工学院,江西抚州344000 [2]核工业地质局208大队,内蒙古包头014000

出　　处：《铀矿地质》2003年第2期94-99,共6页Uranium Geology

摘　　要：本文运用沉积体系理论 ,对东胜地区直罗组的沉积相及沉积体系归属进行系统分析 ,指出直罗组为河流相沉积 ,其河流演化经历了早期辫状河、中期低弯度曲流河和晚期高弯度曲流河 3个阶段。根据气候演变特点将直罗组分为上、下两个岩性段 :下段为温湿条件下的辫状河沉积和低弯度曲流河沉积 ,形成灰色沉积建造 ;上段为干旱炎热条件下的曲流河沉积 ,形成以红色为主的杂色沉积建造。本区铀矿化属河道砂岩型 ,矿化受辫状河道控制 ,主要赋存于辫状河沉积砂体中。同时 。Applying the theory of depositional system,the depositional facies and depositional systems of the Zhiluo Formation in Dongsheng area are systematically analysed,and authors proposed that sediments of the Zhiluo Formation are of fluvial facies,and streams of the Zhiluo time experienced three evolutional stages,namely:the early braided stream,the middle low sinuousity meandering stream and the late high sinuousity meandering stream.Based on features of paleoclimatic evolution,the Zhiluo Formation is divided into two lithological members.The lower lithological member consists of sediments of braided and low sinuousity meandering streams under humid?warm paleoclimatic conditions forming grey sedimentary formation.The upper member is composed of sediments of meandering streams under arid?hot paleoclimatic conditions representing complex?colored (mainly red) sedimentary formation.It is suggested that uranium mineralization in the study area is of channel sandstone type and controlled by braided channel sediments.Besides,the ore?formation conditions for channel sandstone type uranium deposit are preliminarily discussed.

关 键 词：成矿条件 直罗组 沉积体系 辫状河 曲流河 河道砂岩型铀矿床 鄂尔多斯盆地 

分 类 号：P619.14[天文地球—矿床学]